In recent years, in production factories, the degree of manufacturing of a wide variety of products in small quantities in which a large number of products are manufactured according to a variety of market demands has been increased, and in one production line, a plurality of production items often need to be produced. In a case where a wide variety of products are manufactured on the same production line in a mixed manner, the numbers of components, processing methods and assembly methods are different when the products to be produced are different, and operation times necessary in individual steps differ when the number of steps in a production line differs, producing a problem that does not occur in the production of a single product.
For example, when a wide variety of products are manufactured on the same production line, various types of waste are produced. Specifically, when operation times necessary in individual steps differ depending on products, variations in the operation times of the individual steps are produced which produces standby times in the individual steps. In order to manufacture different products, it is necessary to perform a so-called stage replacement such as the change of jigs. Although it is necessary to timely supply necessary components to necessary steps according to the production plan of each product in the logistics of a factory, when a wide variety of products are manufactured, the supply of components becomes complicated.
Conventionally, in order to cope with such a problem, the analysis of effects of simulation technology in a production line has been utilized. The simulation of a production line is performed by a technology that is generally referred to as discrete simulation. In this discrete simulation, software is used to set facility elements of products, machines, workers and transport means such as forklifts; and operations developed by the facility elements and conditions for the development. The relationship of the development thereof is then evaluated and the behavior of the production line is predicted (see patent literature 1).
Specifically, specific operations developed by the facility elements, conditions for developing the specific operations of the facility elements, and various factors such as operation times of the specific operations and required amounts such as the number of necessary components are set for each facility element, and other facility elements are set as output destinations to which information that the specific operations are completed is notified when the specific operations are completed. A setting is then made such that the specific operations of the other facility elements are developed according to the output of the specific operations. In other words, the facility elements are networked and defined.
The specific operations are developed on the facility elements serving as the root of the production process network, thereby propagating the development of the specific operations to the facility elements of the production process network extended to the root and proceeding computation of the simulation and simulating a state where the production on the production line proceeds. By recording the start time and the completion time of the specific operations of the facility elements and the number of components consumed in this simulation, the time progress of an operation time ratio in the facility elements and the time progress of the number of components consumed can be predicted, and the total time (lead time) needed for the production of one product, the state of component supply logistics such as whether or not components prepared in a component warehouse or a component rack are missing and the time at which they went missing and the like can be predicted, with the result that it is possible to analyze problems in a production line before the start of mass production.